While loop in Ruby Shoes GUI ToolKit

Question

I have only been using Shoes for a few days now so maybe I am missing something. I wrote my son an little program to help him learn his multiplication tables. When he gets ten correct he's done. I can not seem to get the while loop right using SHOES. Would some please show me a while statement. When I try; it either wipes out my flow and stack statements or Shoe crashes.

thanks in advance. Sam

Answer 1

I don't know how you're using a while loop. Most likely you're trying to recreate the stack each iteration through the while loop, which is a bad idea. The two solutions that spring immediately to mind are to handle the logic on a button click and keep track of the number correct in a row, like this:

Shoes.app do
  num_correct = 0
  first_num = 1 + rand(10)
  second_num = 1 + rand(10)
  answer = first_num * second_num

  stack do
    @info = para 'Hi, Timmy!  This program will test your ',
           'multiplication tables.  When you get 10 ',
           'correct, you get to stop, and you get your ',
           'pet hamster back!'
    @question = para "What is #{first_num} x #{second_num}?"
    @response = edit_line :width => 100
    btn = button 'OK' do
      if @response.text == ''
        alert('You need to put an answer in the box, Timmy.')
      elsif @response.text.to_i == answer
        num_correct += 1
        if num_correct == 10
          @info.text = "Good job!  That's #{num_correct} in a row!"
          alert('You did it, Timmy!  You can have your ' \
                  'hamster back... for now.')
          exit
        else
          @info.text = "Good job!  That's #{num_correct} in a row!"
          first_num = 1 + rand(10)
          second_num = 1 + rand(10)
          answer = first_num * second_num
          @question.text = "What is #{first_num} x #{second_num}?"
          @response.text = ''
        end
      else
        num_correct = 0
        @info.text = "Wrong, Timmy.  The answer is #{answer}."
        first_num = 1 + rand(10)
        second_num = 1 + rand(10)
        answer = first_num * second_num
        @question.text = "What is #{first_num} x #{second_num}?"
        @response.text = ''
      end
    end
  end
end

Or, the solution which I think is much more interesting, using url and visit:

class MyTest < Shoes

  url '/', :index
  url '/correct/(\d+)', :correct
  url '/wrong/(\d+)', :wrong
  url '/question', :question
  url '/question/(\d+)', :question
  url '/done', :done

  def index
    stack do
      para 'Hi, Timmy!  This program will test your ' \
             'multiplication tables.  When you get 10 ' \
             'correct, you get to stop, and you get your ' \
             'pet hamster back!'
      button 'OK' do 
        visit '/question'
      end
    end
  end

  def question(num_correct = 0)
    num_correct = num_correct.to_i
    first_num = 1 + rand(10)
    second_num = 1 + rand(10)
    answer = first_num * second_num
    stack do
      para "What is #{first_num} x #{second_num}?"
      flow do
        response = edit_line :width => 100
        button 'Answer' do
          if response.text.to_i == answer
            num_correct += 1
            if num_correct == 10
              visit '/done'
            else
              visit "/correct/#{num_correct}"
            end
          else
            visit "/wrong/#{answer}"
          end
        end
      end
    end
  end

  def correct(num_correct)
    stack do
      para "Good job!  That's #{num_correct} in a row!"
      button "Next Question" do
        visit "/question/#{num_correct}"
      end
    end
  end

  def wrong(answer)
    @num_correct = 0
    stack do
      para "Wrong!  The correct answer is #{answer}."
      button "Next Question" do
        visit '/question'
      end
    end
  end

  def done
    stack do
      para 'You did it, Timmy!  You can have your ' \
      'hamster back... for now.'
      button 'OK' do
        exit
      end
    end
  end
end

Shoes.app